CN112512443B

CN112512443B - Surgical tool with support structure

Info

Publication number: CN112512443B
Application number: CN201980050548.8A
Authority: CN
Inventors: 罗兰-阿洛伊斯·霍格尔; 拉尔夫·菲斯特; 安德烈·比尔克
Original assignee: Aesculap AG
Current assignee: Aesculap AG
Priority date: 2018-09-10
Filing date: 2019-09-09
Publication date: 2024-02-23
Anticipated expiration: 2039-09-09
Also published as: WO2020053149A3; CN112512443A; DE102018122025A1; WO2020053149A2; DE102018122025B4; EP3849436A2

Abstract

The invention relates to a surgical tool (1), in particular a milling or drilling tool for surgery, comprising a tool shank (2) which has an actuator (4) on its distal end section and a coupling structure (6) on its proximal end section, wherein the coupling structure (6) is adapted to be coupled rotationally fixed and axially fixed to a drive which is accommodated in a housing, preferably in a handpiece, in order to thereby transmit the rotation of the drive to the tool shank (2), wherein at least one pivot bearing (8) is arranged between the tool shank (2) and the housing, preferably the handpiece, for rotatably supporting the tool shank (2) on the housing, preferably the handpiece. The pivot bearing (8) is connected with the tool shank (2) to form a unit which can be inserted into the housing as a whole to be coupled with the drive and can be withdrawn from the housing to be decoupled from the drive.

Description

Surgical tool with support structure

Technical Field

The present invention relates to a surgical tool having a support structure.

Background

Several surgical tools, such as surgical milling tools or drilling tools, are known from the prior art, which have a tool shank comprising a proximal and a distal end section, which is a working end with an actuator. The tool can be coupled with its proximal end section via a coupling structure in a rotationally fixed and axially fixed manner to the drive in the housing in order to transmit the rotational movement of the drive to the tool, which can then be rotated about its longitudinal axis with actively operated devices. In order to provide the necessary support for the tool relative to the housing, this housing has a pivot bearing firmly integrated therein. The tools are usually interchangeably connected to the housing, so that the housing can be used several times and can be provided with different or different types of tools.

Such a tool is known, for example, from document US RE 29 736, wherein the tool is implemented as a surgical drill. The tool shank has a circumferential running groove near its proximal end in which a ball firmly accommodated in the composite housing for supporting the tool relative to the housing can be looped. The tool shank is axially movable relative to the housing. If these balls are defective, the portion of the housing in which they are accommodated must be replaced.

Furthermore, a surgical tool with a support structure is known from document US 9,175,723 B2. The tool is rotatably supported in the housing shaft by a plurality of ball bearings toward its proximal end section. The tool is supported on the housing shaft toward its distal tip section by needle bearings. All pivot bearings are firmly integrated in the housing shaft or in the housing.

In this case, the problem is that such pivot bearings, which support the tool in the housing and are wear parts, are subjected to large loads in the housing, such as corrosion, contamination and overload. While housings with these pivot bearings integrated therein are often used. This may damage the pivot bearings such that they are defective and must be repaired or replaced. During repair or replacement, the housing or hand piece cannot be used as intended, and therefore time and cost are expended for the user of the tool.

Disclosure of Invention

It is therefore an object of the present invention to improve the usability of a housing with a drive that can be coupled with a surgical tool relative to at least one bearing that supports the tool in the housing.

The solution according to the invention for achieving the above-mentioned object consists in a surgical tool, in particular a milling or drilling tool for surgery, having a tool shank with an actuator on its distal end section and a coupling structure on its proximal end section, which is used and adapted to be coupled, optionally in torsion and axially fixed, with a drive accommodated in a housing (or housing shaft), preferably a handpiece, in order to thereby transmit the rotation of the drive to the tool shank, for which purpose at least one pivot bearing is arranged between the tool shank and the housing, preferably the handpiece, for rotatably supporting the tool shank on the housing, preferably the handpiece. According to the invention, the pivot bearing is connected with the tool shank to form a unit which can be inserted into the housing as a whole to be coupled with the driver and can be withdrawn from the housing to be decoupled from the driver.

In other words, a surgical tool, in particular a surgical milling tool, is proposed, which has a tool shank and distal and proximal end sections. The tool is inserted with its proximal end section in the housing/handpiece in a replaceable manner and is coupled in a rotationally fixed and axially fixed manner to a drive in the housing in order to be able to carry out a rotational movement of the drive about its longitudinal axis. The tool is supported in the housing by at least one bearing/pivot bearing/bearing element. In this case, the pivot bearing is connected to the housing and (axially) fixedly to the tool in such a way that it forms a unit with the tool shank, preferably as a snap-fit connection or as a plug-in connection.

Thus, the pivot bearings may be updated independently of the handpiece or housing, and optionally with the tool, without the need to undergo maintenance of the housing. Therefore, the failure of the pivot bearing can be greatly reduced. If the pivot bearing fails, the tool with the fixedly integrated pivot bearing is replaced or only the pivot bearing itself, which in this case is detachably accommodated on the tool shank, is replaced, so that the respective handpiece can continue to be used for its intended purpose. The user can, if desired, simply and quickly automatically perform the replacement of the pivot bearing or the tool with the pivot bearing for the handpiece each time the tool is replaced. This ensures a high usability and reliability of the handpiece. Cost and/or time are saved for the user of the surgical tool according to the invention by means of a pivot bearing which can be exchanged independently of the handpiece.

Preferably, a rolling bearing is used as pivot bearing, which has a bearing inner section comprising guides, an outer section comprising guides, and a cage between this bearing inner section and this outer section, which cage has rolling bodies supported therein, which rolling bodies are arranged between the guides of the bearing inner section and the bearing outer section. Rolling bearings, in particular ball bearings, are generally of annular design and are mounted on the tool shank in such a way that the pivot bearing and the tool shank are coaxial with one another. As an alternative, a plain bearing can also be used as pivot bearing, which has no rolling elements between its inner bearing section and its outer bearing section.

The pivot bearing is preferably integrally formed with the tool shank, in particular is press-fitted to the tool shank, such that the tool shank or tool forms a non-detachable unit with the pivot bearing, and the tool is preferably a disposable tool.

If the pivot bearing is formed integrally with the tool shank, it may be advantageous to renew the pivot bearing each time the tool is replaced, so that the tool is a disposable tool. The pivot bearing is non-detachably connected to the tool shank in such a way that the bearing inner section is press-fitted to this tool shank. If the pivot bearing and the tool form a non-detachable unit, this pivot bearing allows better running performance and no sliding between the pivot bearing and the tool shank occurs. In addition, the bearing capacity of the pivot bearing is improved, and the load capacity of the pivot bearing is further improved.

As an alternative to a pivot bearing which is integrally formed with the tool, this pivot bearing can be constructed separately from the tool shank, in particular be fitted onto the tool shank, so that the tool shank or the tool and this pivot bearing form a detachable unit.

An advantage of this embodiment is that the tool is independent of wear of the pivot bearing and that the tool can be used multiple times. Furthermore, the user can simply replace the pivot bearing by himself, if desired, for example, using a ball bearing cartridge.

In a further embodiment, the tool shank can have at least one radially encircling and in particular coaxially embodied and/or integrally formed projection between the proximal end section and the distal end section for axially fixing the pivot bearing. In this case, this projection directly contacts the pivot bearing by means of its side facing the proximal end section.

The projection serves as a protection for the pivot bearing and prevents an undesired axial displacement of this pivot bearing in the direction of the distal tip section. Such a projection is particularly desirable in the case of pivot bearings that are constructed (e.g., sleeved) separately from the tool shank. Furthermore, in the case of using the rolling bearing as a pivot bearing, this projection prevents damage to the rolling elements.

Preferably, the projection may be tapered in the axial direction, in which case the radial dimension of the projection increases from the distal tip section towards the proximal tip section, preferably until the radial dimension of the projection is at least as large as the outer radial dimension of the pivot bearing. Alternatively, the protrusions may be planar. Furthermore, this projection may have at least only a certain size, such that its radial dimension corresponds to the radial dimension of the bearing inner section. The larger the protrusion, the better its effect of fixing the pivot bearing.

The tool shank, which is connected to the pivot bearing in a non-detachable manner, preferably has at least one radially encircling running groove, which accommodates the pivot bearing, so that the running groove is part of the pivot bearing.

Constructing the running groove on the tool shank as part of a pivot bearing is an alternative solution to press fitting the bearing inner section onto the tool shank. In the case of such a working groove, the bearing inner section of the pivot bearing is omitted and this pivot bearing is not mounted on the tool in a replaceable manner, but can be replaced with the tool only when the tool is replaced. In the case of a rolling bearing, the rolling elements with the outer bearing section are applied directly to the tool shank. The advantage of not having an inner bearing section is that the pivot bearing has less one component and therefore this component cannot wear or break, thus allowing longer use of the pivot bearing and improving its reliability. The production costs of such pivot bearings are also lower compared to conventional pivot bearings having a bearing inner section. In this embodiment, which optimizes the installation space, the pivot bearing is a fixed component of the tool. Furthermore, in the case of the running groove assuming the function of the bearing inner section, the structural dimensions of the pivot bearing can be reduced compared to conventional pivot bearings, resulting in a finer working end. Alternatively, the pivot bearing load rating may be increased, which helps to improve bearing life and stability. In addition, higher rated loads also allow for greater distances between the pivot bearing and the distal tip section. Thus, both reduced structural size and increased rated load of the pivot bearing are advantageous for access and viewing when using surgical tools.

Furthermore, the running groove can be embodied in the form of a groove-like depression on the outer circumferential surface of the tool shank or as a region between two radially encircling lips which are axially spaced apart from one another and which protrude, for example, perpendicularly from the outer circumferential surface of the tool shank.

Such a recess can be introduced into the tool shank simply and at low cost (for example by turning). At the location where the running groove is constructed as a groove, the thickness of the tool shank is less than the thickness of the area adjoining it. Thus, this groove may be a nominal breaking point of the tool shank, but at least minimizes the load carrying capacity of the tool. Alternatively, the running groove can also be embodied such that two radially encircling lips protrude from the surface of the tool shank, which lips are at a distance from one another in the axial direction of the tool shank. This running groove is thus built up in the area enclosed by the two lips. In this case, the tool shank has a constant material thickness radially below the running groove and in the axially adjoining region. In any case, this running groove must be constructed in such a way that it achieves the purpose of guiding the inner section of the bearing.

In a preferred embodiment, the pivot bearing has at least one first snap-in section on its outer circumferential surface, the housing is intended to have a second snap-in section cooperating with the at least one first snap-in section, the first and second snap-in sections being snapped into each other in a snapped-in state, thereby helping to support the tool shank relative to the housing.

Wherein the first snap section may be a snap flange and the second snap section may be a recess and vice versa. The purpose of this snap connection is to prevent the transmission of the rotational movement of the driver or tool to the bearing outer section. That is, this bearing outer section is not capable of rotational movement. If a tool with a fixedly mounted pivot bearing is inserted into the housing, the snap-on collar snaps into a recess provided for this purpose in the snapped-on state. In order to release the snap connection between the housing and the bearing, only a pulling force is applied to the tool, by means of which the snap connection can be released. This facilitates simple and quick tool installation or simple and quick tool removal.

Furthermore, the pivot bearing may be a single, double or multiple row pivot bearing. The pivot bearing may also be a single-row, double-row or multi-row plain bearing, which, unlike a rolling bearing, has no rolling elements.

Multi-row pivot bearings have a higher load carrying capacity than single row pivot bearings and therefore have a longer service life and a higher load carrying capacity. Sliding bearings are particularly suitable for low speed (lower tool speeds) applications.

According to the invention, a surgical tool system is also proposed, which has a housing and a surgical tool, which can be coupled in a rotationally fixed and axially fixed manner to a drive in the housing in order to carry the rotational movement caused by the drive, and which has a pivot bearing on its tool shank, which is firmly connected to the tool shank, and which supports the tool relative to the housing.

Drawings

Embodiments of the surgical tool according to the present invention are described in detail below with reference to the accompanying drawings. Wherein like elements are designated by like reference numerals. These embodiments are merely exemplary and the present invention is not limited to these embodiments.

FIG. 1A shows a surgical tool having a pivot bearing mounted on the tool;

FIG. 1B shows a portion of FIG. 1A and shows a pivot bearing and a portion of a tool shank carrying the pivot bearing;

FIG. 2A shows a portion of a tool shank having a pivot bearing mounted thereon and a projection adjacent the pivot bearing;

FIG. 2B shows a portion of a tool shank having a pivot bearing mounted thereon and a modified protuberance adjacent to the pivot bearing;

FIG. 2C shows a portion of a tool shank having a pivot bearing mounted thereon and a further modified projection adjacent to the pivot bearing;

FIG. 2D shows a portion of the tool shank having a pivot bearing mounted thereon and a further modified projection adjacent to the pivot bearing;

FIG. 3A shows a portion of a tool shank having a pivot bearing and a running groove configured as a groove;

FIG. 3B shows a portion of a tool shank having a pivot bearing and a running groove built between two lips;

fig. 4 shows the portion of the tool shank with the duplex bearing.

Detailed Description

Embodiments of the present disclosure are described below based on the drawings.

Fig. 1A shows a surgical milling tool 1 with a tool shank 2, which tool shank 2 has a main section 3, an actuator 4 on a distal end section and a coupling structure 6 on a proximal end section. The actuator 4 is embodied here as a milling cutter, but may also be a drilling machine. The tool shank 2 tapers towards its distal tip section. The coupling structure 6 is narrower in radial dimension than the tool shank 2 for easy insertion into a housing or hand piece (not shown). A drive (not shown) is provided in the housing, with which the tool 1 can be coupled via the coupling structure 6 in such a way that the tool assumes the rotational movement caused by the drive. In case the tool 1 rotates, a supporting mechanism between the tool 1 and the housing is required. Thus, according to the invention, a pivot bearing 8 is provided on the tool shank 2, which pivot bearing 8 is firmly connected to the tool shank 2. The pivot bearing 8 is arranged here on or near the central transverse axis of the tool shank 2, but in any case in the main section 3 of this tool shank.

Fig. 1B shows a portion of fig. 1A. In the present embodiment, the pivot bearing 8, which is connected to the tool shank 2 to form a unit, is embodied as a ball bearing, but may alternatively be another rolling bearing or a sliding bearing. The pivot bearing has an inner bearing section 10, a guide 12 located on the inner bearing section, balls (rolling elements) 14 and an outer section 16. In all of the figures (fig. 1A, 1B and 2A-2D) showing the pivot bearing 8 with the bearing inner section 10 mounted on the tool shank 2, the pivot bearing 8 can be slipped (releasable connection) or press-fit (non-releasable connection) onto the tool shank 2. In other cases where the ball bearing 8 of the bearingless inner section 10 is mounted on the tool shank 2 by a running groove (fig. 3A, 3B and 4), this running groove is part of the ball bearing 10 and replaces the bearing inner section 10 of this ball bearing.

As shown in fig. 1B, the ball bearing 8 has an axially extending snap flange 18 on its outer peripheral surface. But the ball bearing may have a plurality of snap flanges 18. These snap-in flanges 18 are adapted to snap into corresponding recesses (not shown) in the housing provided for this purpose in order to prevent the outer section 16 of the ball bearing 8 from assuming the rotational movement of the drive in order to facilitate the support between the tool and the housing. The bearing inner section 10 is firmly connected with the tool shank 2: the bearing inner section 10 is slipped onto the tool shank 2, whereby the pivot bearing 8 is constructed in a manner detachable from the tool 1/independent of this tool, or the bearing inner section 10 is firmly press-fitted onto the tool shank 2, so that the tool 1 and the pivot bearing 8 adopt a non-detachable/integral construction scheme. In any case, the tool 1 or the tool shank 2 forms a unit with the ball bearing 8.

Fig. 2A shows a part of the tool shank 2 with the ball bearing 8. The projection 20 directly adjoins the ball bearing 8 in the direction of the distal tip section of the tool 1. The projection 20 is constructed in such a way that its maximum radial dimension on the side in contact with the ball bearing 8 is as large as the outer radial dimension of the ball bearing 8. In the present embodiment, the protrusion 20 has a flange shape. The projections 20 serve as protection means against undesired displacement of the pivot bearing towards the actuator 4 when the milling tool 1 is used in line with the intended destination. The boss 20 can protect the pivot bearing that is provided (thus constructed separately) and press-fit (thus constructed integrally) onto the tool shank from sliding toward the actuator. In addition, the protrusions 20 also prevent the balls 14 from being damaged. Therefore, the projection 20 has a protective function against the ball bearing 8. The projection 20 is formed integrally with the tool shank 2 and comes into contact with one end side (facing the proximal end section) of the pivot bearing 8.

Fig. 2B shows a protrusion 20 in an alternative embodiment. The projection 20 is planar, and the radial dimension of this projection 20 is the same over its entire height and corresponds to the radial dimension of the outer circumference of the ball bearing 8.

Fig. 2C shows another alternative embodiment of the protrusion 20. In this case, the projection 20 is conical, in particular, the projection 20 is configured in such a way that the projection 20 tapers in its radial dimension from a radial dimension on the side contacting the ball bearing 8, which is here as large as the outer radial dimension of the ball bearing 8, to a radial dimension which is here only slightly greater than the radial dimension of the tool shank 2.

Fig. 2D shows a modified bump 20 as compared to the previously described embodiment of the bump 20. The radial dimension of this projection 20 is only as large as the outer radial dimension of the bearing inner section 10, so that the entire pivot bearing 8 is not prevented, but only the displacement of the bearing inner section 10 in the axial direction towards the distal tip section. Such shortened projections may be of flange-like, planar or tapered embodiments as compared to other embodiments.

Fig. 3A shows a part of the tool shank 2 with a running groove in the form of a radially encircling groove 22, which serves as a guide 12 for the balls 14 of the ball bearing 8. Therefore, the bearing inner section 10 of the ball bearing 8 is unnecessary and omitted. The recess 22 is embodied as a recess with respect to the outer surface of the tool shank 2, so that the tool shank 2 is narrower here than in the remaining main section 3 of the tool shank 2.

Fig. 3B shows a part of the tool shank 2 with an alternative embodiment to fig. 3A having a running groove, which is defined as the region between two lips 24 which radially surround and are spaced apart from one another in the axial direction of the tool shank 2. These lips 24, which are mountain-shaped, rise from the outer surface of the tool shank 2 and are constructed and spaced apart from one another in such a way that these lips 24 can receive the balls 14 of the pivot bearing 8. The thickness of the tool shank 2 at the location of the running groove is thus the same as in the remaining tool main section 3, and this tool shank is even thickened at the level of the two lips 24.

Even though not shown, the tool shank 2 may also have a plurality of pivot bearings 8, which are integrally or independently constructed, and thus may also have a plurality of projections 20 or running grooves, which are constructed in the same or different ways.

Fig. 4 shows a part of the tool shank 2, which forms a unit with the double ball bearing 26. The double ball bearing 26 is a double row ball bearing. For guiding the balls 14, the tool shank 2 has two radially encircling running grooves in the form of two grooves 22, in which a set of balls 8 is encircling, at a distance from each other in the axial direction. Thus, the dual ball bearing 26 does not have an inner bearing section 10. Even though not shown, three or more rows of pivot bearings may be used. The double or multiple row pivot bearings may also have bearing inner sections and be fitted or press-fitted onto the tool shank 2, which are protected by the projections 20.

The embodiments shown here can generally be combined with one another as long as technically possible.

Reference numeral table

1. Surgical tool

2. Tool handle

3. Tool handle main section

4. Actuator located on distal tip section of tool

6. Coupling structure on proximal end section of tool

8. Pivot bearing

10. Bearing inner section

12. Guide for rolling bodies on an inner bearing section

14. Rolling element (ball)

16. Bearing outer section

18. Buckle flange

20. Protrusions

22. Groove

24. Lip portion

26. Multi-row bearing

Claims

1. Surgical tool (1) with a tool shank (2), which tool shank (2) has an actuator (4) on its distal end section and a coupling structure (6) on its proximal end section, which coupling structure (6) is adapted to be coupled rotationally fixed and axially fixed with a driver in order thereby to transmit the rotation of the driver to the tool shank (2), characterized by at least one pivot bearing (8), which pivot bearing (8) is provided for rotatably supporting the tool shank (2) on a housing, wherein

The pivot bearing (8) is connected with the tool handle (2) to form a unit which can be inserted into the housing as a whole to be coupled with the driver and can be withdrawn from the housing to be decoupled from the driver,

the pivot bearing (8) is integrally formed with the tool shank (2) such that the tool shank (2) of the tool (1) and the pivot bearing (8) are connected together to form a non-detachable unit.

2. Surgical tool (1) according to claim 1, characterized in that the tool shank (2) has at least one radially encircling projection (20) between the proximal end section and the distal end section for axially fixing the pivot bearing (8), such that the side of the projection (20) facing the proximal end section by means of it directly contacts the pivot bearing (8).

3. Surgical tool (1) according to claim 2, characterized in that the projection (20) is axially tapered, in which case the radial dimension of the projection (20) increases from the distal end section towards the proximal end section.

4. Surgical tool (1) according to claim 1, characterized in that the tool shank (2) has at least one radially encircling running groove, which is part of the pivot bearing (8).

5. Surgical tool (1) according to claim 4, characterized in that the running groove is constructed in the form of a groove (22) or as a region between two radially encircling lips (24) which are axially spaced apart from one another, the lips (24) rising from the outer circumferential surface of the tool shank (2).

6. Surgical tool (1) according to claim 1, characterized in that the pivot bearing (8) has at least one first snap-in section on its outer circumference,

the housing presets a second snap section cooperating with the at least one first snap section, and

the first and second snap sections snap together in a snapped state, thereby helping to support the tool shank (2) relative to the housing.

7. Surgical tool (1) according to claim 1, characterized in that the pivot bearing (8) is a double or multiple row pivot bearing (8).

8. Surgical tool system with a housing and a surgical tool (1) according to any of the preceding claims 1 to 7, characterized in that the tool (1) can be coupled in a rotationally fixed and axially fixed manner with a drive in the housing in order to take up the rotational movement caused by the drive, and that the tool has on its tool shank (2) a pivot bearing (8) firmly connected to the tool shank, which pivot bearing (8) supports the tool (1) relative to the housing.